ID Opinion 06-2 2006-03-09

Does the Swan Falls Agreement let Idaho prioritize aquifer recharge over Idaho Power's hydropower water rights, and do later statutes give Idaho Power vested rights against that?

Short answer: This is the original Opinion 06-2, since superseded by Opinion 06-2A. The conclusions are unchanged: Idaho Power's hydropower rights above the Murphy Gauge minimum flows are subordinated to subsequent beneficial uses approved by the State, including aquifer recharge. Idaho Code §§ 42-234(2) and 42-4201A(2) created only an incidental statutory benefit for Idaho Power that the State remains free to modify.

Disclaimer: This is an official Idaho Attorney General opinion. AG opinions are persuasive authority but not binding precedent. This summary is for informational purposes only and is not legal advice. Consult a licensed Idaho attorney for advice on your specific situation.

Plain-English summary

This is the original Idaho Attorney General Opinion 06-2 (March 9, 2006). It was promptly superseded by Opinion 06-2A (February 13, 2007), which corrected scriveners' errors, added two supporting citations, and clarified a footnote about the minimum flow at Milner Dam. The substantive conclusions in both versions are identical. For the corrected, authoritative version of this analysis, see Opinion 06-2A.

The opinion responded to Idaho House Speaker Bruce Newcomb's questions about the Eastern Snake Plain Aquifer recharge. The AG concluded that under the 1984 Swan Falls Agreement, Idaho Power Company subordinated its hydropower water rights above agreed-upon minimum flows at the Murphy Gauge to all subsequent beneficial upstream uses approved by the State. That includes aquifer recharge. Two later statutes (Idaho Code §§ 42-234(2) and 42-4201A(2), enacted in 1994) made aquifer recharge rights "secondary" to Idaho Power's hydropower rights, but the AG concluded those statutes created only an "incidental statutory benefit" that the legislature remains free to modify or rescind. They did not create vested rights in Idaho Power.

Currency note

This opinion was issued in 2006. Subsequent statutory amendments, court decisions, or later AG opinions may have changed the analysis. Treat this page as historical context, not current legal advice. Verify current law before relying on any specific rule, deadline, or remedy mentioned here.

This version of the opinion was explicitly superseded the next year by Opinion 06-2A. Anyone researching the AG's analysis of the Swan Falls Agreement and aquifer recharge should rely on 06-2A as the authoritative version. Both opinions are decades old; the underlying statutes (Idaho Code §§ 42-234, 42-4201A, 42-203B, 42-203C) and case law have evolved, including the Idaho Supreme Court's 2007 ruling in American Falls Reservoir Dist. No. 2 v. IDWR. Verify current law before relying on any specific rule.

Common questions

Q: Why are there two versions of Opinion 06-2?
A: The original 06-2 was issued in March 2006 with several scriveners' errors. The Attorney General reissued the corrected version as 06-2A in February 2007, with two added supporting citations and a clarifying footnote about Milner Dam. The substance is the same; the difference is editorial.

Q: What is the Swan Falls Agreement in one sentence?
A: A 1984 settlement between Idaho, Idaho Power, and the AG that resolved a dispute over Idaho Power's Snake River hydropower water rights by transferring legal title above agreed minimum flows to the State as trustee, with Idaho Power retaining equitable title until the State approves a subsequent upstream beneficial use.

Q: Did the 1994 statutes give Idaho Power any new rights?
A: According to the AG, no. The statutes made aquifer recharge "secondary" to Idaho Power's hydropower rights subordinated under Swan Falls, but the AG read that as an incidental statutory benefit the legislature could modify at any time, not a vested right Idaho Power could enforce against the State.

Q: Why does this opinion matter for the Eastern Snake Plain Aquifer?
A: Aquifer recharge programs depend on the State's ability to allocate water to recharge that would otherwise flow downstream to Idaho Power's facilities. The AG's reading of the Swan Falls Agreement preserved State flexibility to do exactly that.

Q: Does this opinion bind Idaho Power or the courts?
A: AG opinions are persuasive but not binding. Idaho Power could (and did) press contrary positions in subsequent litigation. The opinion's value is as a statement of the State's litigating position and a guide to how the AG would advise the State to proceed.

Background and statutory framework

The Swan Falls Agreement settled litigation arising from Idaho Power Co. v. Dept. of Water Resources, 104 Idaho 575 (1983), which held that Idaho Power had not expressly subordinated its Swan Falls dam hydropower rights but remanded for consideration of whether other theories (abandonment, forfeiture, estoppel, customary preference) might have effected subordination. Rather than litigate those theories, the parties agreed in 1984 to a trust structure: Idaho Power's water rights above the agreed minimum daily flows at the Murphy Gauge (3,900 c.f.s. April-October, 5,600 c.f.s. November-March) would be held in trust by the State of Idaho. The State retained authority to reallocate that trust water to subsequent beneficial upstream uses approved in accordance with state law.

Aquifer recharge had been recognized as a beneficial use in Idaho since 1978 (Idaho Code § 42-4201 et seq.) and in other states by the early 1980s. In 1994, the Idaho Legislature enacted Idaho Code §§ 42-234(2) and 42-4201A(2), making rights for aquifer recharge "secondary to all prior perfected water rights, including those water rights for power purposes that may otherwise be subordinated by" the Swan Falls Agreement. The question presented to the AG was whether those 1994 statutes gave Idaho Power a vested right that would prevent the State from later prioritizing aquifer recharge over Idaho Power's hydropower use.

Citations and references

Statutes:
- Idaho Code § 42-203B (trust water rights)
- Idaho Code § 42-203C (criteria for reallocation)
- Idaho Code § 42-234(2) (aquifer recharge / Swan Falls reference)
- Idaho Code § 42-4201 et seq. (Ground Water Recharge Act)
- Idaho Code § 42-4201A(2)

Cases:
- Idaho Power Co. v. Dept. of Water Resources, 104 Idaho 575 (1983)
- Miles v. Idaho Power Co., 116 Idaho 635 (1989)
- Clear Lakes Trout Co. v. Clear Springs Foods, 141 Idaho 117 (2005)
- Tolley v. THI Co., 140 Idaho 253 (2004)
- Pinehaven Planning Bd. v. Brooks, 138 Idaho 826 (2003)

Source

Landing page: https://www.ag.idaho.gov/office-resources/opinions/
Original PDF: https://ag.idaho.gov/content/uploads/2018/04/Opinion06-2.pdf

Original opinion text

Best-effort transcription from a scanned PDF with significant OCR artifacts. The corrected and authoritative version is Opinion 06-2A. Minor errors may remain, the linked PDF is authoritative.

STATE OF IDAHO
OFFICE OF THE ATTORNEY GENERAL
LAWRENCE G. WASDEN

ATTORNEY GENERAL OPINION 06-2

Hand Delivered

Honorable Bruce Newcomb
Speaker of the House
Idaho House of Representatives
STATEHOUSE
Per Request for Attorney General's Opinion
Regarding Swan Falls Agreement and Idaho Code §§ 42-234(2) and 42-4201A(2)

Dear Speaker Newcomb:

This opinion responds to the questions in your letter dated February 27, 2006, regarding the effect of Idaho Code §§ 42-234(2) and 42-4201A(2) on the use of natural flow to recharge the Eastern Snake Plain Aquifer. In order to respond to your questions, it is first necessary to review the Swan Falls Agreement and to then consider the effect, if any, of Idaho Code §§ 42-234(2) and 42-4201A(2) on the Swan Falls Agreement. The questions presented are set forth below.

QUESTIONS PRESENTED

Is aquifer recharge a use to which Idaho Power Company subordinated its hydropower water rights under the Swan Falls Agreement?
If Idaho Power Company subordinated its water rights to recharge under the Swan Falls Agreement, do the provisions in Idaho Code §§ 42-234(2) and 42-4201A(2) change the Swan Falls Agreement and create any vested rights or priorities in Idaho Power Company?

CONCLUSIONS

Under the Swan Falls Agreement, Idaho Power Company subordinated its hydropower water rights in excess of the agreed-upon minimum flows to all "subsequent beneficial upstream uses upon approval of such uses by the State in accordance with State law," regardless of the type or kind of beneficial use. Thus, the hydropower rights referenced in the Swan Falls Agreement are subordinated to aquifer recharge in accordance with state law.
Idaho Code §§ 42-234(2) and 42-4201A(2) do not create any vested rights or priorities in Idaho Power Company because the State, as trustee, holds legal title to the water placed in trust and, in accordance with the Swan Falls Agreement, the State has the right to determine how the trust water will be used. Idaho Code §§ 42-234(2) and 42-4201A(2) create only an incidental statutory benefit in favor of Idaho Power that the State is free to modify or rescind at any time.

[The full analysis follows in the linked PDF, including a section-by-section reading of the 1984 Agreement, extensive review of legislative history (Statement of Legislative Intent for SB 1008, Senate Resources & Environment Committee minutes from January and February 1985, and February 11, 1985 House Resources hearing), and discussion of the integration clause at paragraph 17 of the Agreement (subsequent legislation does not affect the Agreement's validity). The full opinion runs approximately 13 pages.]

DATED this 9th day of March, 2006.

LAWRENCE G. WASDEN
Attorney General

Analysis by:
CLIVE J. STRONG
MICHAEL ORR
Deputy Attorneys General

Note: Superseded by Opinion 06-2A (February 13, 2007).